The present invention relates to a PCI-based computer system incorporating a mid-plane connector board. More particularly, it relates to a computer system including a chassis and mid-plane connector board configured to load and operate CompactPCI form factor system processor cards at both front and back sides thereof.
Peripheral component interconnect (PCI) bus architecture is widely used for a variety of different computer systems, ranging from desktop or notebook personal computers, to industrial-type computer systems, such as network servers. In this regard, industrial and/or embedded computer systems require a more robust mechanical form factor as compared to desktop-type applications, due to the harsh environment in which these systems are normally operated, and the high performance application requirements. To this end, a consortium known as the PCI Industrial Computer Manufacturers Group (PICMG(copyright)) has promulgated the CompactPCI(copyright) specification that uses industry standard mechanical component and high performance connector technologies to provide an optimized system intended for rugged applications. The CompactPCI specifications are described in CompactPCI specification, by PICMG, 301 Edgewater Place, Suite 500, Wakefield, Mass. and is available at www.picmg.org. PICMG and CompactPCI are registered trademarks of the PCI Industrial Computer Manufacturers Group.
In addition to prescribing a variety of bus and software parameters, the CompactPCI specification defines a form factor for boards or cards insertable and operational with a CompactPCI acceptable computer system. As a point of reference, a CompactPCI computer system generally includes an outer chassis and a backplane board (or simply a xe2x80x9cbackplanexe2x80x9d) forming various connectors and bus circuitry. Of course, a number of other components are also provided, such as power supply unit, hard disk drive, cooling fan, etc. Nonetheless, the chassis and the backplane combine to define a series of slots into which the auxiliary PCI cards are inserted. The PCI cards, or more particularly CompactPCI form factor cards, widely vary in terms of configuration and function, ranging from system processor cards to peripheral or I/O cards, such as digital control cards, relay control cards, etc.
With the above in mind, the CompactPCI card form factor includes 3U cards (100 mmxc3x97160 mm) and 6U cards (233.35 mmxc3x97160 mm). In addition, the maximum unit width (or thickness) of the CompactPCI form factor card (and related components disposed thereon), and thus of each slot defined by the chassis and backplane, is established as 20.32 mm (or card center-to-center spacing). This width is oftentimes referred to as a CompactPCI unit width, or simply a xe2x80x9cunit widthxe2x80x9d.
In light of the above-described CompactPCI form factor requirements, the xe2x80x9cstandardxe2x80x9d CompactPCI chassis design defines a front panel or side and a back panel or side. The backplane is oriented parallel with the front and back panels, thereby establishing a front region and a back region. Further, the backplane is normally positioned more closely to the back panel. Due to this offset location, the front region is much deeper than the back region. For example, the typical CompactPCI chassis/backplane configuration provides the front region with a depth of approximately 8 inches and the back region with a depth of approximately 4 inches. Thus, the front region of a standard CompactPCI computer system chassis is configured to load and operate the various CompactPCI cards, whereas the back region can only serve as a transition zone for receiving one or more transition modules related to the card inserted at the corresponding front side slot. More particularly, the backplane forms a feedthrough connector at one or two of the defined front slots. A card, and in particular a system processor card, inserted into that front slot is connected to the feedthrough connector (along with a system processor bus connector). An auxiliary card, otherwise related to the system processor card, can then be inserted into the corresponding back same slot, and is connected to the front slot card via the feedthrough connector. Effectively, then, the offset positioning of the backplane facilitates the provision of extended capabilities for a card that is inserted into a corresponding front slot.
The above-described xe2x80x9cstandardxe2x80x9d CompactPCI chassis/backplane design is universally accepted and quite viable. However, this design limits the number of system processor cards usable with the computer system. In particular, the chassis/backplane load provides CompactPCI form factor slots at the front; including normally one or two system processor card slots, with the remaining slots being reserved for peripheral or I/O cards. If a normal, CompactPCI system were to be fully loaded with processor cards, the processor cards must be limited to occupy only a single unit width slot; or alternatively, the system would sacrifice usable slots to cards that are wider than a single unit width slot. The limited size of the back region, along with the bus architecture and feedthrough connector form of the backplane, prevents loading of system processor cards in the back slots, in turn limiting the overall capabilities of the computer system.
An additional concern associated with the standard CompactPCI chassis design is an inability to service the computer system from either the front or the back. In this regard, one common application for industrial computer systems is in the telecommunications industry, which restricts loading/servicing to the front side only. More recently, however, as CompactPCI chassis designs move into the ISx markets (that typically utilize deeper racks), dual side loading/servicing has become desirable. Due to the extremely large number of functions and processed data associated with telecommunications activities, a large number of computer systems must be employed in tandem. The common practice is to mount a series of computer systems in a component rack. A number of these racks are then stored side-by-side in a centralized location. Servicing of any one particular computer system at the front side is relatively straightforward, as the operator is able to identify the computer system in question. Unfortunately, servicing of a component via the back side of that same computer system by a single technician can be cumbersome as it is difficult to identify the proper computer system from a plurality of racked components. As a result, two operators are required; one standing at the front side, and the other standing at the back side. In this way, the front side operator can confirm that the back side operator has properly located the computer system in question.
In addition, an operator standing at the back side of the computer system has no way to control or otherwise access functioning of the front slots (and associated cards), and vice-versa. Conversely, an operator servicing the computer system from either the front side or the back side is unable to prevent another operator from unknowingly interrupting a particular service operation from an opposite side of the computer system. Thus, a technician standing at the back side may unintentionally override servicing efforts of another technician working at the front side, and vice-versa.
CompactPCI computer systems continue to be highly popular. However, opportunities for improved capabilities and servicing remain. Therefore, a need exists for a CompactPCI-based computer system configured to receive and operate multiple system processor cards, and/or facilitate servicing thereof, from either the front or back.
One aspect of the present invention relates to a CompactPCI-based computer system including a chassis and a mid-plane board. The chassis houses various electrical components, and defines a front and a back. The mid-plane board is analogous to a xe2x80x9cbackplanexe2x80x9d utilized with CompactPCI computer systems, and forms bus circuitry. The mid-plane board is positioned between the front and back of the chassis. With this in mind, the chassis and the mid-plane board combine to define a plurality of CompactPCI form factor slots, including front slots extending from the front of the chassis to the mid-plane board, and back slots extending from the back of the chassis to the mid-plane board. Further, at least one of the front slots and at least one of the back slots are system slots configured to receive and provide independent bus connections for respective CompactPCI form factor system processor cards. In one preferred embodiment, the mid-plane board is equidistantly positioned between the front and back of the chassis, establishing symmetrical front and back regions. In another preferred embodiment, respective ones of the front slots are aligned with respective ones of the back slots such that the front and back slots include aligned first slots and second slots. In other words, the chassis and mid-plane board combine to form a first front slot aligned with a first back slot, and a second front slot aligned with a second back slot. With this in mind, the mid-plane board is configured such that the first front slots provide a bussed connector, whereas the first back slot provides a transition connection to the first front slot. Conversely, the second back slot provides a bussed connector, whereas the second front slot provides a transition connection to the second back slot. With this one preferred embodiment, a one- or two-unit wide system processor card can be loaded into the first front slot, and another one- or two-unit wide system processor card can be loaded into the second back slot.
Another aspect of the present invention relates to a CompactPCI-based computer system including a chassis, a mid-plane board, a first system processor card, and a second system processor card. The chassis houses various electrical components and defines a front and a back. The mid-plane board is positioned between the front and back of the chassis and forms bus circuitry. Further, the chassis and the mid-plane board combine to define a plurality of CompactPCI form factor slots, including front slots extending from the front to the mid-plane board and back slots extending from the back of the chassis to the mid-plane board. The first system processor card is inserted within one of the front slots. Conversely, the second system processor card is inserted within one of back slots. With this in mind, the mid-plane board is configured to provide independent bus connections for each of the first and second system processor cards. In one preferred embodiment, the computer system further includes a first control panel and a second control panel. The first control panel is located on the front of the chassis and is configured to control operations of all the front and back slots. The second control panel is located on the back of the chassis and is also configured to control operation of all of the front and back slots. With this one preferred embodiment, then, control over all slots, and thus of the cards inserted therein, as provided from either the front or back of the chassis.
Yet another aspect of the present invention relates to a method of manufacturing a CompactPCI-based computer system. The method includes providing a chassis including a front and a back. A mid-plane board is also provided. The mid-plane board includes a front side, a back side, and a plurality of bussed connectors on both the front and back sides. The mid-plane board is mounted within the chassis between the front and back such that the front side faces the front of the chassis and the back side faces the back. The chassis and the mid-plane board combine to define a plurality of CompactPCI form factor slots, including front slots extending from the front of the chassis to the mid-plane board, and back slots extending from the back of the chassis to the mid-plane board. At least one of the front slots and at least one of the back slots are configured to receive and independently operate respective CompactPCI form factor system processor cards.